Soyfood consumption and risk of glycosuria: a cross-sectional study within the Shanghai Women's Health Study

OBJECTIVE: To assess the association between soyfood intake and risk of glycosuria. DESIGN AND METHODS: A cross-sectional study was conducted among participants of the Shanghai Women's Health Study, a population-based cohort study of women aged 40-70 y. Information on usual intake of soyfoods was obtained at baseline survey through an in-person interview using a validated food-frequency questionnaire. Included in this study were 39,385 cohort members screened for diabetes at the baseline survey and free of previously diagnosed diabetes, cardiovascular diseases, kidney diseases, and cancer. There were 323 women who tested positive for urine glucose. Odds ratios (ORs) and 95% confidence intervals (CIs) were employed to measure the association between soyfood intake and glycosuria using unconditional logistic regression. SETTING: Urban communities of Shanghai, China. RESULTS: Overall, soyfood intake was not related to the risk of glycosuria. Among postmenopausal women, however, intake of tofu and other soy products was inversely associated with risk of glycosuria after adjustment for potential confounders. The ORs across quintiles of intake were 1.0, 0.75 (95% CI=0.47-1.20), 0.79 (95% CI=0.51-1.25), 0.53 (95% CI=0.32-0.88), and 0.51 (95% CI=0.26-0.98; P for trend=0.05). Further analyses showed that the inverse association was primarily confined to postmenopausal women with a body mass index (BMI) of <25 kg/m2. The adjusted OR comparing the extreme quintiles was 0.36 (95% CI=0.13-0.97; P for trend=0.004). CONCLUSIONS: Soyfoods may play a role in the development of glycosuria, an important indicator of diabetes, among postmenopausal women with a low BMI.